Technical Field
The embodiments herein generally relate to an uninterrupted power supply (UPS) device, and, more particularly, to drive a load containing a switched mode power supply circuit amid increasing use of the switched mode power supply based loads.
Description of the Related Art
Nowadays, deficit of the power supply is common in India. The scarcity of the power supply is high in rural areas when compared to the urban areas. Also the power distribution to the rural areas is less compared to the urban areas. Due to short time disruptions and scheduled disruptions of the power supply, most of the companies and technology based computer services related industries shy away from rural areas. This problem is not only for the companies and the industries but also for the common people who are all living in rural areas. An uninterrupted power supply (UPS) technology was invented for reducing the power disruption problem.
In the prior art, the uninterrupted power supply converts AC power supply to DC then save the DC power in a battery that is connected with the UPS when the main supply is ON. The uninterrupted power supply then reverses the process of converting the power when the main supply is OFF. The circuit uses a relay and hence momentary glitches can occur and these are detrimental to operation of electronic circuits such as modems which rely on a continuous signal and may take considerable time to resynchronize. FIGS. 1A-1B show typical types of UPS connected to loads. The FIG. 1A is an OFF line UPS 102A, where the loads are switched from AC to AC supply generated from a battery using an inverter. The OFF Line uninterruptible power supply 102A includes a battery charging unit, a 12 v 7 Ah battery, DC-AC Converter, and a load. This Off Line uninterruptible power supply 102A is connected to lights and when the electricity goes away, the lights are shut off. The battery is charged when the AC power is turned on and as soon as the AC power is switched off, then the battery starts generating a voltage up till 230V. The load is then turned on to the 230V that is generated by the battery. The load is then turned off for some time and then turned back on again. This is for a very small duration and the switchover time could be even micro seconds. The load switched from DC to AC supply generated from the battery by making use of an inverter. The main drawback of an OFF Line uninterruptible power supply is that there is a glitch which is produced at the output.
The FIG. 1B is an ON line UPS 102B, where the AC charges the battery. The ON Line uninterruptible power supply 102B includes a battery charging unit, a 12 v 7 Ah battery, DC-AC Converter, and a load. This uninterruptible power supply is more expensive when compared to the OFF Line uninterruptible power supply 102A. The basic working followed here is that the main AC input that is given charges the battery. The battery produces up till 230V and the circuit producing this 230V is always on. There is also a hand held unit which produces that power up to 2 to 3 CFL's, small loads. The AC voltage produces charging of the battery and when the AC goes off, the oscillator helps to generate 50 Hz 230V. There are no glitches at the output, hence the design runs smoothly. The main disadvantages of an ON Line uninterruptible power supply 102B is that the overall efficiency is less because the inverter always remains on and never turns off. Also, the power consumed by the charging unit is very high because it has to supply power to the inverter and also supply power for charging the battery simultaneously. The loads are always connected to the AC supply generated from the battery using the inverter. Here modems run correctly since no glitches occur in the output. The ON line UPS 102B is an AC generator that is always ON to generate the AC supply voltage to the electrical loads.
Typical UPS are used to limit power disruption, the usage of power supply from the UPS to the loads, more expensive, and low efficiency. Hence, overall usage of the power is high, but the supply is scarce. Accordingly, there remains a need for an uninterrupted power specifically to efficiently collect charge when line is working and supply that to loads when required. The emergency lighting units are primarily maximizing useful life for use on full charge and not necessarily for most economical transfer of energy.